February Challenge 2017
Chef and Triangles, Chef and His Apartment Dues, Most Frequent Element
March Challenge 2017
Xenny and Alternating Tasks, Bear and Extra Number, (CH) Bear and Sorted Rows, Bandwidth of a matrix
September Challenge 2017
Little Chef and Sums, Chef and Pick Digit, Minimum Good Permutation
January Challenge 2018
K-Concatenation, Maximum Score, Rectangle
September Challenge 2018 Division 2
Magician versus Chef, Bad Shuffle, Chef and Adventures
February Challenge 2020 Division 2
The Theatre Problem, School of Geometry, Hard Cash
March Challenge 2020 Division 2
Ada Bishop 2, Pintu and Fruits
India